| /* Copied from libtomcrypt/src/prngs/sprng.c and modified to |
| * use Dropbear's genrandom(). */ |
| |
| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| * |
| * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com |
| */ |
| #include "options.h" |
| #include "includes.h" |
| #include "dbrandom.h" |
| #include "ltc_prng.h" |
| |
| /** |
| @file sprng.c |
| Secure PRNG, Tom St Denis |
| */ |
| |
| /* A secure PRNG using the RNG functions. Basically this is a |
| * wrapper that allows you to use a secure RNG as a PRNG |
| * in the various other functions. |
| */ |
| |
| #ifdef DROPBEAR_LTC_PRNG |
| |
| /** |
| Start the PRNG |
| @param prng [out] The PRNG state to initialize |
| @return CRYPT_OK if successful |
| */ |
| int dropbear_prng_start(prng_state* UNUSED(prng)) |
| { |
| return CRYPT_OK; |
| } |
| |
| /** |
| Add entropy to the PRNG state |
| @param in The data to add |
| @param inlen Length of the data to add |
| @param prng PRNG state to update |
| @return CRYPT_OK if successful |
| */ |
| int dropbear_prng_add_entropy(const unsigned char* UNUSED(in), unsigned long UNUSED(inlen), prng_state* UNUSED(prng)) |
| { |
| return CRYPT_OK; |
| } |
| |
| /** |
| Make the PRNG ready to read from |
| @param prng The PRNG to make active |
| @return CRYPT_OK if successful |
| */ |
| int dropbear_prng_ready(prng_state* UNUSED(prng)) |
| { |
| return CRYPT_OK; |
| } |
| |
| /** |
| Read from the PRNG |
| @param out Destination |
| @param outlen Length of output |
| @param prng The active PRNG to read from |
| @return Number of octets read |
| */ |
| unsigned long dropbear_prng_read(unsigned char* out, unsigned long outlen, prng_state* UNUSED(prng)) |
| { |
| LTC_ARGCHK(out != NULL); |
| genrandom(out, outlen); |
| return outlen; |
| } |
| |
| /** |
| Terminate the PRNG |
| @param prng The PRNG to terminate |
| @return CRYPT_OK if successful |
| */ |
| int dropbear_prng_done(prng_state* UNUSED(prng)) |
| { |
| return CRYPT_OK; |
| } |
| |
| /** |
| Export the PRNG state |
| @param out [out] Destination |
| @param outlen [in/out] Max size and resulting size of the state |
| @param prng The PRNG to export |
| @return CRYPT_OK if successful |
| */ |
| int dropbear_prng_export(unsigned char* UNUSED(out), unsigned long* outlen, prng_state* UNUSED(prng)) |
| { |
| LTC_ARGCHK(outlen != NULL); |
| |
| *outlen = 0; |
| return CRYPT_OK; |
| } |
| |
| /** |
| Import a PRNG state |
| @param in The PRNG state |
| @param inlen Size of the state |
| @param prng The PRNG to import |
| @return CRYPT_OK if successful |
| */ |
| int dropbear_prng_import(const unsigned char* UNUSED(in), unsigned long UNUSED(inlen), prng_state* UNUSED(prng)) |
| { |
| return CRYPT_OK; |
| } |
| |
| /** |
| PRNG self-test |
| @return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled |
| */ |
| int dropbear_prng_test(void) |
| { |
| return CRYPT_OK; |
| } |
| |
| const struct ltc_prng_descriptor dropbear_prng_desc = |
| { |
| "dropbear_prng", 0, |
| &dropbear_prng_start, |
| &dropbear_prng_add_entropy, |
| &dropbear_prng_ready, |
| &dropbear_prng_read, |
| &dropbear_prng_done, |
| &dropbear_prng_export, |
| &dropbear_prng_import, |
| &dropbear_prng_test |
| }; |
| |
| |
| #endif /* DROPBEAR_LTC_PRNG */ |